The present invention relates to a pack for cylindrical, hamburger-type sandwiches. More generally, it relates to a pack for any rather compact food presented in a cylindrical shape and intended to be eaten in the pack.
The hamburger being the most popular cylindrical sandwich, the descriptions shall be based on the application to the wrapping of hamburgers, as the wrapping of hamburgers is a delicate operation, inasmuch as it deals with a soft, open and layered sandwich, with dripping sauces and greasy debris which can fall and soil the consumer's clothing if the hamburger is not systematically supported from beneath in its pack during the entire consumption time.
There are two principal known types of hamburger packs-one is a hinged box in the shape of double trays, generally of square cross section, with a snap-in locking system. Currently, for environmental reasons these packs are preferably made of a light-weight flat or micro-flute paperboard; these trays are preformed in an automatic gluing operation.
The hamburger is placed flat in the lower tray, and the consumer must bring it upright, requiring that he delicately slide the index and/or second finger of one hand between the hamburger and the bottom of the lower tray to lift the hamburger with his thumb, in a very uncomfortable gesture, just as uncomfortable as holding the same lower tray with the other hand to protect against spots during consumption, while the upper tray hinged on the lower tray may hit his face during the eating process.
Moreover, children tend to eat the sandwich outside the tray, thereby frequently soiling their clothing.
Other packs are merely very thin rectangular sheets of paper which are wrapped around the hamburger in the manner any flat cylindrical object is wrapped, by tucking the extending edges of the folded paper under the wrapped item.
In addition, there is a very thin, longitudinally pleated wrap, where the pleats are secured at the end by lateral seals, the paper having a polyethylene coating serving as a hot-melt glue to allow it to be sealed.
This manual pack is very difficult to adjust, it is rather unattractive once in place, and has not met with the expected success.
According to another method described in U.S. Pat. No. 4,189,054, a cylindrical box for the packing of round sandwiches consists of two half-shells, each surrounding the sandwich over half of its perimeter, and connected to each other along a single hinge parallel to the generatrix of the cylinder. In the closed position, each shell comes into edge-to-edge contact with the other. During the filling operation, the sandwich is placed upright into the lower shell, and the upper shell is lowered on the lower shell.
During consumption, the sandwich is held in the lower shell which can either be torn along its radius, or folded outward laterally along the hinge in the generatrix of the cylinder. This pack is produced by polyurethane foam molding and has several disadvantages. Since the peripheral and lateral walls are perpendicular to each other and molded, the packs are not stackable; the sandwich is too ensconced at the bottom of one shell while the other shell hits the consumer's face, which is most uncomfortable, particularly during the end phase of consumption as the radial tear-out of the half-shell as well as the lateral tear-out features provided to access the last portion of the sandwich with the mouth are awkward and require a strong pull on the pack which may suddenly give way and possibly dislocate the sandwich, and cause food scraps to shower on the consumer or his neighbors.
To our knowledge, this pack has never actually been used for these reasons.
Differently, U.S. Pat. No. 4,494,785 relates to a precut and prepleated flexible paper napkin destined to partially cover a cylindrical sandwich allowing it to be held in one's fingers without them touching the food. It consists of a strip partially surrounding the periphery of the sandwich and of two series of parallel two-by-two flaps designed to fit between the fingers and the top and bottom of the sandwich respectively. This napkin stays around the sandwich only if it is held by the hand, and does not allow to effectively catch the sauce or greasy scraps escaping from the sandwich during its consumption, nor does it provide for thermal insulation of the hot sandwich.
The very old, German patent 336789 describes a rectangular parallelepiped box with square cross-section and cross-bottom closure obtained through the diagonal folding of the four bottom fields; this box is accessible from the bottom only; it mainly serves to wrap powdered or grain products, and possesses no specific characteristic for eating a round sandwich in its pack, even if one box may serve many different purposes.
U.S. Pat. No. 2,443,531 describes an hermetically sealed cubic box of rather thick paperboard, specifically designed to accommodate a cube of ice cream to be carried under the best possible conditions (mainly of temperature) between the point of purchase and the point of consumption.
The paperboard sheet is divided into equal square areas along three longitudinal strips, delimited by two parallel fold lines and five transversal strips delimited by four fold lines perpendicular to the former.
To consume the content, the box is placed on an horizontal table and redeployed in the plane of the table so that the ice cream remains on the central square area on which it can be cut and served. Granted perhaps that this box may accommodate a hamburger in a specific application, one cannot help but realize that it has not been designed for a hamburger to be eaten in its pack.
The round box disclosed in U.S. Pat. No. 2,224,504 consists of a cylinder made from a sheet of unspecified material, having a central section and lateral extensions, the length of which is exactly half the diameter of the product to be packed.
It is the material of these extensions which, by folding down on both sides of the apertures of the central cylinder along fan-shaped pleats, closes the cylinder and wraps a product compatible with this type of pack which can be opened from either side. The resulting pseudo-box possesses no useful characteristic for a hamburger pack, much less for the consumption of a hamburger from the pack as it does not have a stable sealed bottom.
As we know, it is designed to package deluxe soaps and other perfume items or gifts, preferably having two roughly parallel planes.
The paperboard container described in U.S. Pat. No. 2,295,508 forms a universal box with original assembling and locking, designed to hold fairly large volumes, but as a result has the usefulness of any non-specific traditional box, which was actually the inventor's intent as he was seeking the widest possible application as stated in the text of the patent.
The paperboard container in U.S. Pat. No. 3,031,124 features a very complicated manual folding system in no way suitable to large commercial preforming runs; while the esthetic result is quite pleasing, this satchel shaped pack does not offer any specific application, which was the intent of its inventor. In another perspective, had this pack held any specific interest for the consumption of a hamburger, surely this would have become known since 1959.
In 1963, U.S. Pat. No. 945,399 describes a wrapping process for various articles with a folded sheet, lined or impregnated with polyethylene in particular, but also with aluminum, and especially a means to utilize the lining material to heatseal the organized pleats and seal the pack through the application of a rigid thermoplastic label made from a compatible material and designed to display a brand name outside the pack.
We are far removed here from the concern for a specific hamburger pack.
The analyses of all above-mentioned packs and of many other existing food packs leads to the conclusion that while some of them may be used for a hamburger, none of them, including the currently used hinged boxes and the lined papers, offer nor do they claim to offer all of the required specifications allowing the easy and practical consumption in its pack of a hamburger or another compact food of cylindrical shape.